A Multiscale Model to Simulate the Bone Remodeling Process

Resumo

Bone tissue is a living material under constant activity. Bone response to an external stimulus application
causes renewal of its local properties by the bone remodeling process. The synchronized activities of three bone
cell lineages are related to the process. The osteoblast lineage is responsible for bone formation, while the
osteoclasts are responsible for the resorption process. Finally, the osteocytes cells provide mechanosensitivity to
the bone tissue. An important factor for controlling the cell activity is the OPG-RANKL-RANKL pathway.
Another characteristic of the bone tissue is its multiscale behavior. The behavior at the microscale influences the
properties at the macroscale. In this sense, this study aims to develop a model for simulating the bone remodeling
process. This model considers mechanical, chemical, and biological variables, and the bone multiscale. We use
the finite element method to analyze the remodeling process by using Abaqus and Matlab software. The biological
model considers the interactions between osteoblasts and osteoclasts. Also, the model considers the control
performed by the OPG-RANKL-RANKL pathway. We determine the mechanical stimulus at the microscale using
a representative volume element (RVE). This stimulus interacts with chemical factors. This interaction controls
the bone cell evolution that changes the RVE's volume fractions. Thus, the volume fractions evolution influences
the mechanical properties at macroscale (density and elastic modulus). The BR model allowed characterizing the
structural morphology of a human femur. We observed its main characteristics.